title: Improving carrier injection in colloidal CdSe nanocrystals by embedding them in a pseudomorphic ZnSe/ZnMgSe quantum well structure.
abstract: The incorporation of colloidal nanocrystals in a high crystalline quality semiconductor matrix, the efficient carrier injection into the embedded nanocrystals and the fast optical response are key features for the fabrication of novel optoelectronic nanodevices based on colloidal nanostructures as active optical material. Using a novel growth approach, colloidal bare CdSe and core-shell CdSe/ZnS nanocrystals were monolithically incorporated in pseudomorphic ZnSe/ZnMgSe quantum wells in order to control and enhance the carrier transfer into the nanocrystals. The photoluminescence for bare CdSe nanocrystals incorporated in ZnSe/ZnMgSe quantum well structures is substantially enhanced in comparison to nanocrystals sandwiched in ZnSe epilayers, which we attribute to increased carrier injection into the embedded nanocrystals via the quantum well, resembling the function of a wetting layer in Stranski-Krastanov-grown quantum dots. Core-shell CdSe/ZnS nanocrystals embedded in quantum well structures do not show considerable PL modifications because the ZnS shell prevents the efficient carrier migration between the nanocrystal and the matrix. Systematic investigations of structural and optical properties by high-resolution x-ray diffraction, temperature-dependent photoluminescence and time-resolved emission are presented.
authors.affiliation: Physics Faculty, ICTM, University of Havana, Colina Universitaria, CP 10400 Havana, Cuba. Institut für Optik und Atomare Physik, Technische Universität Berlin, Strasse des 17. Juni 135, D-10623 Berlin, Germany. Department Physik, Center for Optoelectronics and Photonics Paderborn (CeOPP), Universität Paderborn, Warburger Strasse 100, D-33098 Paderborn, Germany.
authors.forename: E M
authors.initials: EM
authors.lastname: Larramendi
authors.forename: O
authors.initials: O
authors.lastname: Schöps
authors.forename: M V
authors.initials: MV
authors.lastname: Artemyev
authors.forename: D
authors.initials: D
authors.lastname: Schikora
authors.forename: K
authors.initials: K
authors.lastname: Lischka
authors.forename: U
authors.initials: U
authors.lastname: Woggon